Agile vs Waterfall

Introduction

This page is dedicated to constructive banter on the advantages and disadvantages of Agile Development compared to Waterfall Development techniques. It seems like people push too hard one way or the other usually, and suffer from over structure and under structure. -- Marcin (presumably)

\- Marcin isn't doing (or understands) either, hence this ignorant critique about structure, which doesn't actually mean anything. He's actually just doing haphazard micromanagement. For example, if either Waterfall or Agile were used to develop the hablab, it would have been developed before 15 people arrived. --Vann

Agile Advantages

• It recognizes that stakeholder's business requirements often change once they see a working product.
• It recognizes that team capacities change as new members come on and leave, that as time goes on designs change or improve and thus time and budget estimates change, as informed by reality, and thus planning very far ahead simply doesn't work. To estimate time, team velocity is measured against user story estimates to give a burn down chart, which gives can give a time estimate -- the way to make a project go faster is to have fewer user stories, more team members (splitting teams as they grow past 9 or so), or improving each member's productivity via training.
• It separates concerns: stakeholders have business requirements aka user stories, and team members self assign tasks they can complete during an iteration. This prevents worker burnout and simultaneously satisfies stakeholders.
• It has been measured to perform 40% faster than waterfall (wikispeed), not counting cumulative effects.
• Workers self assign to tasks and are therefore more satisfied and motivated to work.
• It is significantly more scalable than waterfall; there's minimal overhead in interteam communication and unncessary documentation, in that it prevents management from micromanaging.
• It contributes towards the democratization of the workplace which is an imperative step in the new (distributive) economy. (trustistheonlycurrency, sacred economics)
• It contributes towards a healthier working environment.

Agile Disadvantages

• It's good for iterative creativity, but not to get a big project done ON TIME.

\_ This is a fallacy and ironic. Waterfall projects often go way over budget and way over time, that's a big reason Agile was developed in response! There's nothing magic about waterfall that makes a project happen on time, in fact, if anything, it hides the reasons why projects go over time (not accounting for changes in team capacity, new or changing business requirements, new knowledge acquired since the spec was written, etc etc)

• Consider the place Agile is lacking.. and why you'd want a gantt chart... When there are external constraints.. like the delivery of supplies, that contribute to a critical path and require advance planning and an understanding of relationships between initiatives.. say in order to build a house before winter and there's a 3 month lead time on the roofing etc. This concerns could be easily carried in a scrum-type layout with an added feature showing dependencies.

\_ Agile, and Scrum in particular, think about dependencies in a different way. See [1]; the key is breaking down a user story that has dependencies within it, and prioritize the tasks in order. Keep in mind that in Waterfall, in contrast, there's a huge amount of unnecessary overhead in tracking dependencies that gains you little.

Waterfall Advantages

• It is driven by time and thus enables projects to be delivered on-time regardless of the lives these constraints may impact

\_ The claim it delivers projects on time is definitely false, see above. But it is true that waterfall doesn't protect team members from change orders and the like, or managers who see a deadline and blindly thrash their employees to meet it, ignorant of why the project is slipping, but this is a disadvantage, not an advantage. I suggest someone who's touting waterfall read a little bit about it first rather than just guess. But Marcin isn't doing waterfall anyway so I wonder at the relevance. --Vann

Waterfall Disadvantages

• Old-school, top-down power dynamics.
• Does not account for changes in the stakeholder's requirements, team capabilities, what is learned during a process, nor is the customer shown anything until the dev cycle is done, thus the customer remains uninformed and unable to provide feedback during the dev process. Specs and design are written up front, and the whole project is one giant, long iteration. This is why Detroit takes a decade to build a new car, and Wikispeed takes 3 months.